Slack-adjuster.



R. W. KELLY.

SLACK ADJUSTER.

APPLICATION FILED FEB.18, 1909.

Patented Feb. 15, 1910.

mars sa s AENT FFIE RICHARD W. KELLY, OF LOS ANGELES, CALIFORNIA,ASSIGNOR OF ONE-HALF TO G. E. HARPHAM, OF LOS ANGELES, CALIFORNIA.

SLACK-ADJUSTER.

Application filed February 13, 1909.

To all whom it may concern:

Be it known that I, RICHARD WV. KELLY, a citizen of the United States,residing in the city of Los Angeles, county of Los Angeles, and State ofCalifornia, have invented new and useful Improvements inSlack-Adjusters, of which the following is a specification.

My invention relates to a slack adjuster for use in an automatic airbrake mechanism and the object thereof is to provide a slack adjusterwhich will automatically take up the slack caused by lost motion or wearof the brake shoes. I accomplish this object by the mechanism describedherein and illustrated in the accompanying drawings in which;

Figure 1 is a plan of my improved slack adjuster, and certain portionsof the connecting mechanism. Fig. 2 is a section taken on the line 22 ofFig. 1. Fig. 8 is a section taken on the line 33 of Fig. 1. Fig. 4 is anenlar ed section on the line 44 of Fig. 1 with a portion of the partsbroken away for clearness of illustration.

My slack adjuster is primarily designed for freight car service, andwill be described herein as applied to that service.

In the drawings is a fragment of a brake cylinder of any standardconstruction.

11 is the push bar sleeve to which is rigidly secured the slack adjusterframe 12. This slack adjuster frame is provided along its inner edgewith two push bar channels 13 and 14 best shown in Fig. 8, into whichare received the inner ends 15 and 16 of the push bar head 17. The outerends 18 and 19 of the push bar straddle lever 20 of the brake mechanismand are secured thereto by the bolt 21 which passes through slot 22 inthe outer ends of the push bar and through lever 20. One of the innerends of the push bar, preferably 15, is provided with a pin 23 whichpasses upwardly through a slot 24 in the slack adjuster frame to preventthe push bar from accidentally separating from the slack adjuster frameafter the parts are assembled for use. After the inner ends of the pushbar are passed into the push bar channels, pin 23 is passed through. theslot and secured in the end of the push bar in any suitable manner.

In the outer end of the slack adjuster frame which, as shown in Fig. 1,lies at an angle to the push bar channels, are the adjusting wedgechannels 25 and 26 in which Specification of Letters Patent.

Patented Feb. 15, 1910.

Serial No. 477,527.

are received the edge lugs 27 and 28 of the adjuster wedge 29. Theselugs and channels guide the movement of the wedge and at the same timehold the wedge from separating from the frame.

To the outer edge of frame 12 is secured an L-shaped screw carrying arm30 which is preferably cast integral with frame 12. Revolubly mounted inthis arm is a ratchet wheel 31 having teeth 32. The hub 33 of thisratchet wheel is hollow and internally threaded for the reception of thethreaded shank 34 of the wedge operating bar which has a head 85 that isbifurcated and proyided with channels 36 and 37 as best shown 1n Fig. 4,into which channels are received the end lugs 38 and 39 of the adjusterwedge. Between arm 30 and wedge 29 shank 34 passes through a retainingand brace frame 40 which is secured to arm 30. This retaining frameprevents any longitudinal movement of the ratchet wheel. The hub of theratchet wheel projects through arm 30 and has the outer end 33 squaredfor the reception of a wrench so that when desired the ratchet wheel maybe rotated, thereby moving the wedge in or out as desired. To the outerend of bar 30 is secured the dog operating arm 41.

To the wall 42 of the bottom of the ear is secured a supporting frame 43which passes just below arm 30 so as to guide and support the same. Abracket 44 is also secured to the car and projects downwardly therefrom. Pivotally secured to bracket 44 by bolt 45 is lever 46 having acurved arm 47 secured thereto on the side of said lever ad jacent to arm41. The upper end of lever 46 is preferably forked and in the furcationsis pivotally mounted by bolt 48, dog 49, the rear end of which projectsthrough the furcations and has secured thereto a spring 50. The otherend of the spring is secured to frame 48.

In the operation of my device the parts will be adjusted so as tonormally be in the position shown in Fig. 1 and the travel of the brakepiston will be such that when the brakes are set the travel of arm 41outwardly will just reach to but not engage lever 46. IVhen there is anyslack in the braking apparatus caused by lost motion,

causing arm 41 to engage the lower end of lever 46 which will throw theupper end of the lever toward the brake cylinder and carry dog 49 to theposition shown in dotted lines in Fig. 2, and will throw arm 47 of lever46 downwardly to the position shown in dotted lines so that it will beengaged by arm 41 upon the backward travel of the piston. As the pistontravels backwardly, dog 49 will engage teeth 32 of the ratchet wheel andwhen arm 41 engages the arm on lever 46 it will draw lever 46 to itsvertical position, thereby causing dog 49 to rotate the ratchet wheel.The rotation of the ratchet wheel will cause operating bar 35 to movetoward the push rod thereby causing wedge 29 to move farther through theinner ends of the push rod, and thereby maintain thenormal piston traveluntil more slack is caused. Each reciprocation of the brake piston willtake up slack if the dog 49 is caused to move far enough to engage theteeth of the ratchet wheel. When wedge 29 has been moved its full widthit will then be necessary to have new brake shoes put on and the othermechanism readjusted to the normal position when the wedge will bebrought back to its normal position as shown in Fig. 1.

By this construction it will be observed that a cheap and eflicientmeans is provided for taking up the slack of a braking mechanism, andthat the slack is taken up auto-' matically by mechanism operated by thepis ton travel of the brake cylinder. It will also be observed that themovement of the wedge is effected by the backward travel of the pistonin the brake cylinder when there is no pressure on the parts. Ordinarilydog 49 would only engage one tooth of the ratchet wheel, but if thereshould be eX- cessive slack, the dog would be moved far enough to engagetwo teeth of the ratchet wheel, thereby more quickly taking up theslack. It will also be observed that frame 12 and bar 17 conjoint-1yform a push rod formed of telescopic parts, and that wedge 29 operatesto elongate the push rod as it is forced between the telescopic parts011 the rearward movement of the brake cylinder piston.

Having described my invention what I claim is:

1. A slack adjuster comprising a push rod formed of telescopic parts,one of said parts being secured to the brake cylinder piston and theother part being operatively connected to the brake levers; eXpansiblemeans carried between said telescopic parts; and means to operate saideXpansible means to cause the outer ends of said telescopic partsa pushrod sleeve; an adjuster frame rigidly secured thereto; a push rodtelescopically contained in said frame; eXpansible means slidablymounted in and carried by said frame and bearing against said push rod;and means to operate said expansible means to cause the outer end of thepush rod to remain at a greater distance from the frame upon an abnormaltravel of the brake cylinder piston.

3. In a slack adjuster the combination of a push rod sleeve; an adjusterframe secured rigidly thereto; a push rod having one end telescopicallymovable in said frame and the other adapted to be connected to the brakelever, said ends of said push bar being bifurcated; a wedge adapted tobe passed be tween the bifurcated ends of said push bar contained withinthe adjuster frame; and means to move said wedge between said arms uponthe abnormal travel of the brake piston.

4. A slack adjuster comprising a push rod sleeve; an adjuster framerigidly secured thereto; said frame being provided with push barchannels along its inner edge and having its outer end at an angle tothe push bar channels and having wedge lug receiving channels in itsouter end; a wedge having lugs on one edge thereof adapted to bereceived in the channels in the end of the adjuster frame; an L-shapedarm secured to said adjuster frame; a ratchet wheel revolubly mounted insaid arm, said ratchet wheel having a hollow internally threaded hub; awedge operating bar, externally screw threaded and passing through saidratchet wheel in threaded contact therewith, said bar having a headoperatively and slidably connected to said wedge; a dog operating armsecured to the arm in which the ratchet wheel is mounted; a bracketsecured upon the bottom of the car; a lever pivotally mounted on saidbracket, having its lower end lying in the path of travel of the dogoperating arm whenever said arm makes an abnormal travel; a curved armsecured to said lever and having the point thereof normally lying abovethe path of movement of the do operating arm, and adapted to be moverbehind said arm upon the abnormal travel thereof; and a dog mounted inthe upper end of said lever, and adapted to be thrown. in the path oftravel in the ratchet wheel and behind the same 'upon the abnormaltravel of said wheel.

In witness that I claim the foregoing I have hereunto subscribed my namethis 3rd day of February, 1909.

RICHARD W. KELLY.

